Is Opec likely to remain a big player in the world economy?

50 years ago the oil-rich nations of the world met in Baghdad for a conference which led to the creation of Opec.

In the 1970s the organisation seemed like a world power in its own right as its members hiked oil prices and cut vital supplies of crude to political opponents.

Since then Opec's powers have waned.

Is Opec likely to remain a big player in the world economy for the next 50 years?

Jeremy Howell reports.